SAMPLEDGear, instruments and tools · updated 2026-08-16
KEYBED
The physical key mechanism under a keyboard: synth-action (light, springy), semi-weighted, or hammer-action (piano-like). It decides how the instrument plays more than the sounds do.
Photo: Akai MPC Live (2017) (opens in a new tab) by Joan Recordà (opens in a new tab), via Wikimedia Commons — CC BY-SA 4.0 (opens in a new tab)
Key takeaways
- The physical key mechanism under a keyboard: synth-action (light, springy), semi-weighted, or hammer-action (piano-like).
- It decides how the instrument plays more than the sounds do.
- Synth-action is light and springy and suits fast lines and drums; semi-weighted adds resistance and is the usual compromise; hammer-action mimics a piano's escapement and is heavy, expensive and correct for pianists.
- Play the same piano patch from a synth-action and a hammer-action board; the notes are identical, the dynamics you can hold are not.
- Watch out: confusing 'weighted' marketing language with hammer-action.
Quick checklist
- Can you define keybed in one sentence without looking?
- Can you point at keybed in a real session, mix or contract?
- Have you tried the practical move above at least once?
- Would you catch the common mistake before it costs you a take?
- Have you opened one of the primary sources below rather than a forum thread?
KEYBED IN DEPTH
The keybed is the mechanism under the keys. Synth-action is light and springy and suits fast lines and drums; semi-weighted adds resistance and is the usual compromise; hammer-action mimics a piano's escapement and is heavy, expensive and correct for pianists. Nothing about the keybed changes the MIDI notes — it changes whether you can perform them.
How it works in practice
Play the same piano patch from a synth-action and a hammer-action board; the notes are identical, the dynamics you can hold are not.
The mistake people make
Confusing 'weighted' marketing language with hammer-action. Semi-weighted keys are sprung, not hammered.
WHERE KEYBED SITS
Keybed belongs to gear, instruments and tools in the Sampled music glossary. The boxes, controllers and sample formats a producer is expected to know by name — from the MPC to a one-shot.
TEST YOURSELF
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3 quick questions on keybed. Answers are marked instantly — nothing is sent anywhere.
1. Which statement best describes keybed?
2. What is the mistake people most often make with keybed?
3. In practice, which of these applies to keybed?
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SOURCES AND CITATIONS
Free, primary references for keybed — standards bodies, manufacturers, government offices and university course material. Each one lists the line of this entry it backs up.
- MIDI Association — MIDI articles (opens in a new tab)
Specification owner · The MIDI Association
“The physical key mechanism under a keyboard: synth-action (light, springy), semi-weighted, or hammer-action (piano-like).”— the claim this source supports
Why it counts: The body that publishes the MIDI specification, so this is the definition hardware and software are built against.
- Sampled — best MIDI keyboard controllers
Primary reference · Sampled — best MIDI keyboard controllers
“It decides how the instrument plays more than the sounds do.”— the claim this source supports
Why it counts: Published by the organisation responsible for the thing being defined, so it is a first-hand source rather than a summary of one.
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